feat(desktop): apply friend nicknames in header / bubble / mentions / call tile

apps/desktop/src/components/MentionAutocomplete.tsx

@@ -1,8 +1,11 @@
 import type { ConversationSummary } from '@chat-app/shared/chat';
 import { useEffect, useState } from 'react';
 
+import { useNickname } from '../lib/friendNicknames';
 import { Avatar } from './Avatar';
 
+type Member = ConversationSummary['members'][number];
+
 interface Props {
   members: ConversationSummary['members'];
   query: string;
@@ -63,37 +66,58 @@ export function MentionAutocomplete({ members, query, excludeUserId, onSelect, o
       aria-label="Mitglieder"
       className="absolute bottom-full left-0 right-0 z-20 mb-2 max-h-64 overflow-y-auto rounded-xl border border-line bg-surface-2 p-1 shadow-xl dark:bg-[#2b2d31]"
     >
-      {matches.map((m, idx) => {
-        const name = m.profile?.displayName ?? m.profile?.username ?? '?';
-        const handle = m.profile?.username ?? '';
-        const isActive = idx === active;
-        return (
-          <button
-            key={m.userId}
-            type="button"
-            role="option"
-            aria-selected={isActive}
-            onMouseEnter={() => setActive(idx)}
-            onClick={() => {
-              if (m.profile?.username) onSelect(m.profile.username);
-            }}
-            className={
-              'flex w-full cursor-pointer items-center gap-2 rounded-lg px-2 py-1.5 text-left text-sm transition ' +
-              (isActive
-                ? 'bg-accent/20 text-fg'
-                : 'text-fg-muted hover:bg-surface-3 dark:hover:bg-[#383a40]')
-            }
-          >
-            <Avatar
-              displayName={name}
-              url={m.profile?.avatarUrl ?? null}
-              className="h-6 w-6 text-[10px]"
-            />
-            <span className="min-w-0 flex-1 truncate text-fg">{name}</span>
-            <span className="shrink-0 text-[10px] text-fg-muted">@{handle}</span>
-          </button>
-        );
-      })}
+      {matches.map((m, idx) => (
+        <MemberRow
+          key={m.userId}
+          member={m}
+          isActive={idx === active}
+          onActivate={() => setActive(idx)}
+          onSelect={onSelect}
+        />
+      ))}
     </div>
   );
 }
+
+// Extracted per-row component so we can call `useNickname` once per member
+// at the top of THIS component (hooks can't run inside .map callbacks).
+function MemberRow({
+  member,
+  isActive,
+  onActivate,
+  onSelect,
+}: {
+  member: Member;
+  isActive: boolean;
+  onActivate: () => void;
+  onSelect: (username: string) => void;
+}) {
+  const fallback = member.profile?.displayName ?? member.profile?.username ?? '?';
+  const name = useNickname(member.userId, fallback);
+  const handle = member.profile?.username ?? '';
+  return (
+    <button
+      type="button"
+      role="option"
+      aria-selected={isActive}
+      onMouseEnter={onActivate}
+      onClick={() => {
+        if (member.profile?.username) onSelect(member.profile.username);
+      }}
+      className={
+        'flex w-full cursor-pointer items-center gap-2 rounded-lg px-2 py-1.5 text-left text-sm transition ' +
+        (isActive
+          ? 'bg-accent/20 text-fg'
+          : 'text-fg-muted hover:bg-surface-3 dark:hover:bg-[#383a40]')
+      }
+    >
+      <Avatar
+        displayName={name}
+        url={member.profile?.avatarUrl ?? null}
+        className="h-6 w-6 text-[10px]"
+      />
+      <span className="min-w-0 flex-1 truncate text-fg">{name}</span>
+      <span className="shrink-0 text-[10px] text-fg-muted">@{handle}</span>
+    </button>
+  );
+}